The present disclosure relates to systems and methods for interpolation and decimation in fiber optic communications systems in general and, in particular, to low complexity interpolators for dual polarity fiber optic communications systems.
Fiber optic channels in network communications systems are well known and are considered effective for data transmission, allowing relatively high bandwidth data communication. Optical fiber used in such channels is flexible and may be bundled as cables, and is generally considered to be advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical cables. Typical present day commercial optical fiber systems transmit data at 10 or 40 Gbit per second. Each fiber may carry multiple independent channels, each using a different wavelength of light in a technique known as wavelength-division multiplexing (WDM), thereby enhancing the net data rate of an optical fiber.
As more capacity is continually desired for networks, increased data transmission rates would be desirable. However, in fiber optic systems, as data rates increase the quantity of data required to be processed by demodulation and decoding components increases. Furthermore optical phenomena may introduce distortions and alterations to optical signals that result in received signals that require a significant amount of processing to properly demodulate the received signals. Given the large amounts of data transferred at high data rates and the significant amounts of processing required to demodulate the signals, demodulator architectures can become complex and costly.